Phase formations, magnetic and catalytic properties of Co3O4 hexagonal micro-boxes with one-dimensional nanotubes

Abstract

One-dimensional Co 3 O 4 nanotubes were grown in alignment on the surface of micron-sized Co 3 O 4 hexagonal-box via a mild template-free wet chemical method. The nanotubes are y250 nm in diameter with several micrometers in length. The growth mechanism and phase formation for the vertically grown nanotubes on the surface of the boxes have also been investigated. The intermediates of a-Co(OH) 2 and b-Co(OH) 2 towards the final products of Co 3 O 4 are also characterized. The magnetization, M(T), measurements for the micro-boxes with nanotubes reveals that the Neel temperature is suppressed from the bulk value of 40 K down to 22 K, possibly due to finite size effect. The Curie-Weiss analysis on the paramagnetic behavior above the Neel temperature gives the average effective moment of 4.4 m B per formula unit, slightly higher than 4.14 m B of its bulk counterparts. The electrocatalytic experiments for the oxidation of methanol reveal that the final product exhibits better catalytic performance compared with the intermediate product due to its higher specific surface area.

Role of PVA in synthesis of nano Co3O4‐decorated graphene oxide

“…Co 3 O 4 nanoparticles have been synthesized by different methods such as wet chemical, sol–gel, chemical precipitation, hydrothermal, microwave assisted, and combustion . Among all these methods, the combustion method is a promising technique for the synthesis of Co 3 O 4 nanoparticles.…”

Compositionally controlled band gap and photoluminescence of ZnSSe nanofibers by electrospinning

“…[1][2][3] Amid the group II-VI semiconductors, ZnSSe, as a direct band gap material with a bulk band gap of 2.70-3.5 eV, is considered as a good candidate for light-emitting devices and other optoelectronic devices. [1][2][3] Amid the group II-VI semiconductors, ZnSSe, as a direct band gap material with a bulk band gap of 2.70-3.5 eV, is considered as a good candidate for light-emitting devices and other optoelectronic devices.…”

“…9,10 For these reasons, synthesis of high-quality ZnSe and ZnS nanomaterials is still an attractive topic. 3,[21][22][23] The phase and morphology evolutions of ZnS x Se 1−x in the presence of PVB are systematically studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible spectroscopy, as well as by using a diode pumped solid state laser (DPSS). In semiconductor nanomaterials, band gap energy can easily be handled by slight tuning of their composition and size.…”

Ni(OH)2@Co(OH)2 hollow nanohexagons: Controllable synthesis, facet-selected competitive growth and capacitance property

“…However, ideal hollow nanohexagons have never been reported. Similar nanostructures, such as such as nanosheets [12], nanoflake [9,13,14], and hollow nanostructures [15], [16][17][18][19][20][21][22][23] have widely been synthesized. It is necessary to produce uniform hexagonal structure with controllable size.…”